A solenoid valve has a moving core that can move to both sides in the axial direction, a coil for generating magnetic force that attracts the moving core to one side in the axial direction, and a stator that forms a magnetic circuit in cooperation with the moving core. The stator has a cylindrical part covering the peripheral face of the moving core and an attracting part for attracting the moving core.
There is a known solenoid valve having a cup-shaped member made of a nonmagnetic material, disposed on the inner periphery of the stator, and supporting the moving core so as to be able to reciprocate (for example, JP-2001-187979A). By having the cup-shaped member, fluid can be prevented from leaking to the outside of the cup-shaped member.
In the solenoid valve, the moving core is disposed on the inside in the radial direction of the cup-shaped member. On the other hand, the attracting part of the stator is disposed on the outside in the radial direction of the cup-shaped member, so that the moving core and the attracting part of the stator do not face each other. There is consequently a problem such that the attracting force is insufficient. In particular, when the amount of movement toward the attracting part of the moving core increases and the distance in the axial direction between the moving core and the attracting part is reduced, the rate of change in magnetic flux decreases. Consequently, the attracting force further decreases.